The Parramatta Marist High School is an independent Roman Catholic single-sex secondary day school for boys, located in Westmead, a suburb of the western region of Sydney, New South Wales, Australia.

There has been Catholic education in the Diocese of Parramatta since the first catholic school was established in the Parramatta area in 1820. There are 80 Catholic systemic schools in the diocese with a total student population of around 43,000 and a staff population of around 5,000. There are also six non-systemic or congregational (independent) Catholic schools.